How to create new project to convert RH4 to RH6

I need to convert old RH for Word projects from version 4.1 to RH 6. The problem is that the old project files have names with embbeded spaces. For example, I have a project called Purchase Order.hpj. I tried converting a few of these projects, where the conversion seem to run smoothly, but when I tried to compile new additions or changes, the table of contents and the main project would not show up the converted project.

I have been using the word document, deleting all topics, jumps and links and starting from scratch, but this requires to much effort and time. Is there a better way?